JavaScriptSerializer 在序列化时间datetime类型是会有时区差异

JavaScriptSerializer  与    DataContractJsonSerializer（命名空间System.ServiceModel.Web及System.Runtime.Serialization)

JavaScriptSerializer   在序列化时间datetime类型是会有时区差异，JavaScriptSerializer 会将时间转成utc类型

DataContractJsonSerializer  在序列化时间时对时间类型进行了判断，如果为local类型，则加上时区

因此推荐使用DataContractJsonSerializer 序列化

    public class JsonHelper
    {
        public static string Serialize<T>(T data)
        {
            System.Runtime.Serialization.Json.DataContractJsonSerializer serializer =
            new System.Runtime.Serialization.Json.DataContractJsonSerializer(data.GetType());
            using (MemoryStream ms = new MemoryStream())
            {
                serializer.WriteObject(ms, data);
                return Encoding.UTF8.GetString(ms.ToArray());
            }
        }

        public static T Deserialize<T>(string json)
        {
            T obj = Activator.CreateInstance<T>();
            using (MemoryStream ms =
            new MemoryStream(Encoding.UTF8.GetBytes(json)))
            {
                System.Runtime.Serialization.Json.DataContractJsonSerializer serializer =
                new System.Runtime.Serialization.Json.DataContractJsonSerializer(obj.GetType());
                return (T)serializer.ReadObject(ms);
            }
        }

    }